In the 1960's and 70's a few people started to realise that the consumption of the earth's fuel reserves was becoming excessive. At that time the main concern was that the fossil fuels were limited and would eventually run out. The price of oil went up in the early 1970's. It became more viable to spend more money on searching for more oil, and to extract oil which had a high cost of extraction such as that at sea and also that which occurred in smaller quantities.
There is still the question of using up all available fossil fuel, but global warming has become an issue of higher priority.
It is now well known and universally accepted that global warming is caused by carbon dioxide (CO2) being released into the atmosphere. CO2 in the atmosphere causes a phenomenon known as the greenhouse effect. In a greenhouse heat enters through the glass at a higher rate than it leaves. This causes the temperature inside to increase and so be warmer than the outside. Something similar happens to the world as a whole where a layer carbon dioxide allows more heat in than it lets out.
The biggest and most obvious threat of global warming is rising sea level. This is caused mainly by the melting of ice on land in the cold regions of the world. By far the greatest part of this is in Antarctica.
A big problem with global warming is that the warming takes place long after the cause. When CO2 is emitted it stays in the atmosphere for hundreds of years and continues to cause the earth to heat up. Even if mankind could completely stop emitting CO2, the temperature of the earth would continue to rise due to the CO2 which is already there. Adding further to the CO2 will cause that temperature rise to accelerate. But it's worse than that. As the temperature of the earth rises, several factors will make things worse. Here are some of them:
Even if the world's CO2 emissions remain as they are, or reduce slightly, in 10-20 years time the warming process will have already gone too far to be reversed and the eventual melting of the Western ice cap will become inevitable, athough it will take 100-200 years to do so. The only way of preventing this occurring in the future is to dramatically reduce CO2 emissions within the next 20 years. That is reduce, not simply stop increasing.
It doesn't look likely, the way things are going. The CO2 we are putting into the atmosphere is greater than it has ever been. What is worse, despite all environmental concerns, it is still increasing, in fact it is increasing faster than ever before.
The consequence of these things means that there is a theshold for the temperature of the earth and CO2 levels which represents a point of no return. Once exceeded these additional warming factors will take over and cause the earth's temperature to go on increasing even if we were to completely stop emitting CO2.
One of the great problems ot things which cause environmental damage is the delay between the initial cause, and the ultimate consequences. Global warming from CO2 is one example. Burning fossil fuels puts CO2 into the atmosphere, but that then causes global warming to take place very gradually over a period of years, but goes on doing so even if we were to stop emitting any more CO2.
Another example is rising population. People, in common with other animals take a very short-sighted view to having children. If they are prosperous this year, they will have a child now, but do not consider that the child will be with them for perhaps 18 years. Indeed as far as the planet is concerned that new person will go on consuming, and emitting CO2 for perhaps 70 years.
We have evolved to respond immediately to adversity. If we do something which has adverse consequences we stop, but the consequences of our action on the planet are very gradual, and in any case, it may be too late to stop.
It is HUMAN BEINGS who use fossil fuels, emit CO2, and cause global warming. No other animal or plant would cause ANY global warming. Of course people in the more civilized world emit far more CO2 than the poor people of the third world, but generally the emission of CO2 is proportional to the number of people. Over-population is probably the biggest single factor which causes global warming.
Our actions on this planet will almost certainly will make the earth largely uninhabitable for us. Our population will decline considerably and it is questionable whether civilization as we know it can survive. What is particularly tragic is that we will by then have caused extinction of a great many other animals and plants who are not to blame.
See also my page on this site: population.html
Here are some facts about Antarctica:
Antarctica consists of Eastern and a Western ice caps. The Eastern ice cap is the larger, the Western ice cap has 10-15% of all the ice.
The Eastern ice cap is not under serious threat of melting in the foreseeable future, but if it did it would cause a massive 80 metres rise in sea level.
The Western ice cap is very likely to break away and melt, and if it does so entirely it will cause a rise of sea level of 5-6 metres. Most of the world's population lives at low levels and close to the sea.
An ice floe larger than greater London has recently broken off.
The Arctic differs significantly from Antarctica because the Arctic consists mainly of frozen water, not ice on top of land. This ice is largely already underwater and so melting it will not contribute to the increase in water in the oceans. However, the Arctic serves as an indicator of what his happening to global average temperatures, and will also have its own powerful effect. When viewed from space the ice on the earth's surface is white and reflective, and it simply reflects back much of the heat from the sun back into space. If the ice in the Arctic melts much of this heat previously reflected back will instead be absorbed, so adding greatly to the heating of the planet.
Recently scientists have found that the ice in the Arctic is melting faster than was anticipated and previously thought. Some believe that the north pole itself could be melted and accessible by ships in as little as 30 years.
Professor James Lovelock is a highly respected scientist and has written on environmental issues for many years. He conceived of the Gaia principle in the 1970's which recognises the whole earth as acting in a similar way to a living organism and regulates the conditions on earth to make it suitable for life to be sustained. His concusions from the latest scientific knowledge, including the UK government's Hadley Centre (link below), are that we have passed the point of no return no matter what we do about CO2 production. The rate of increase in temperature is already considerable, but it is being temporarily reduced by a shading effect from particles in the atmosphere which are being produced by our emissions. As we reduce these emissions this shading effect will also reduce and reveal the real underlying temperature increase to be higher than ever.
James Lovelock believes that most of the earth will become a hot desert. The ability for mankind ot survive will be greatly reduced and the earth will sustain only a very small population living in the extreme north and south of the planet. Many other species of both animals and plants will face extinction. The earth has been in a similar state before. James Lovelock believes that once the planet enters such a state it will take 100,000 years before it returns to something like it is now.
In his book "The Revenge of Gaia" published February 2006, professor Lovelock reluctantly accepts the role of the bearer of very bad news for mankind. As worldwide environmental pressures increase Britain will have to be able to grow its own food, something which is only just possible. Apart from individual details like the inevitable flooding of London he envisages an eventual breakdown in society, the loss of our techological capabilities, and mankind reduced to a rabble led by warlords. These things will start to happen in the next 100 years.
"Each nation must find the best use of its resources to sustain civilisation for as long as they can".
Even if mankind substantially dies out the damage will already have been done, and the earth will no longer be able to support the lives of many other species of plants and animals.
Britain is trying to meet its emission targets specified in international agreements. However Britain is responsible for only a small part of world emissions, the worst being, by far, the USA. The developing countries, notably China are of concern because of the huge increase taking place in their industrialisation. The political thinking in Britain is that we should at least meet the targets ourselves or else how could we seriously attempt to persuade other countries to comply.
The same applies to each individual. When a whole country such as Britain can make such a small difference, then how much less is it for just one man.
The dilemma for each individual and country is that alone we cannot have much of an impact. However, how can we preach to others that they must reduce their CO2 emissions if we do not first do so ourselves?
It is fashionable to do our bit towards helping the environment, but often this is only lip-service. Tiny little concessions to the environment which are only done because they do not hurt. I have heard people speaking on the radio advocating such tiny measures as switching off little DC adaptors when they are not in use. They quote some figure about how much electricity would be saved if everyone in the country turned off one of these. Well sorry, but it's trivial and virtually useless. One can estimate the amount of power consumed by an electrical device by the amount of heat it gives off, in fact there is a precise relationship. This does not only mean how hot the device or appraratus is, but we must also count other heat lost such as the hot water drained from a washing machine.
The fact is that it is large appliances which use a lot of heat which consume the most electricity, and so cause CO2 production. Electric heaters, washing machines, dishwashers and perhaps the worst offender of all, tumble dryers. The reason tumble dryers are particularly offensive is because they are used for convenience and not necessity. Naturally occurring energy is difficult to harness. Even could outside air contains some heat but it usually cannot be utilised. However it can be used for drying washing where the use of high grade, concentrated energy from electricity for this purpose would be very wasteful.
Scientists believe that Venus and the Earth were formed very similarly when the solar system was formed. There are sufficient differences in the two planets for their developments to diverge over the millions of years of their existence, for example Venus is closer to the sun. Venus can be regarded as something like the Earth might have become if the greenhouse effect had escalated the way it did on Venus. It has a huge atmospheric pressure, high temperature and an acidic humid environment, and would be completely impossible for any life we know of.
Mars shows another way a planet can develop. It has a thin atmosphere, it is scorched by the sun, and is almost completely devoid of water. It might have once had water but this has now all evaprated away into space.
In the 1990's scientists considered the idea of 'terraforming' Mars, that is using large scale interventions to artificially create an atmosphere and make it possible for some limited form of human habitation. It is clearly a huge task in practical engineering terms, but look at it another way. We cannot even control our own atmosphere here on earth to keep it inhabitable for the future, even though our starting point is that it is already perfect.
Global warming is caused by one sort of pollution, notably CO2, but there are other forms of pollution which are of concern though quite separate from global warming. Sometimes the concern is simply a waste of resources, but the main problem is the effect of waste materials on the environment. The most immediate concern is pollution of water by obnoxious and toxic substances. Secondly, there is the build-up of waste on the land. In the normal course of nature, waste products (such as wood for example) will decay. The problem is with man made substances such as plastics. Many plastics will take thousands of years to decay, so leaving them in the environment will cause them the gradually build up without end.
These are some terms frequently encountered in discussions about the environment. I have taken the opportunity of adding comments where applicable.
A consequence of coal fired power stations. Acidic gases such as sulphur dioxide and oxides of nitrogen make the rain acidic. Can be solved by eliminating the emissions of these gases at the power station, and in Europe at least has been so solved.
Usually refers to the oceans. They become slightly more acidic due to presence of greater amount of carbon dioxide in the atmosphere. This can cause an impact on the natural organisms in the oceans, and on coral.
These are fuels grown as plants, as distinct from fossil fuels. Although they produce carbon dioxide when burnt, the growing of biofuels absorbs an equal amount of carbon dioxide as they will ultimately give off, so there is no consequent addition of CO2 to the atmosphere. Biofuels may be burnt in power stations, for example wood can replace coal, or may be used to power internal combustion engines, for example vegetable oil can replace diesel.
The chemical element present in fossil fuels and which gives rise to carbon dioxide when the fuels are burnt.
This is where carbon is removed from the emissions of power stations, i.e. the CO2 is captured. This is still more of a theoretical possibility than it is actually done in practice.
Carbon dioxide is a universal product of combustion of all practical fuels. It is virually imperceptible and is emitted even if there is no smoke or smell. It is emitted even by very clean and efficient petrol engines and not removed by catalytic convertors. It is one of the main greenhouse gases. On this page I use the expression CO2, but it is more correctly depicted as:
Carbon monoxide is a result of incomplete combustion. It is poisonous and a local hazard, but not of concern to global warming.
Climate change is often used synonymously with global warming. Both are a consequence of the greenhouse effect arising from carbon dioxide and methane in the upper atmosphere. Where global warming is an average temperature over the whole world, climate change is the practical consequence of it which emphasises the various changes of climate which might occur including changes to rainfall patterns, storms etc.
The process by which fertile land becomes desert. Particularly arising from changes of rainfall patterns due to climate change.
Fossil fuels are those fuels which are extracted from the ground, such as coal and oil. The use of such fuels is a one-way process. Their extraction is a removal of carbon-rich material from the earth, and their combustion results in that carbon going into the atmosphere permanently and irreversibly (except on very long time scales).
The effect where the average surface temperature of the earth is increasing resulting in climate change. Global warming has occurred very gradually in the past but is now happening very rapidly due to the effect of greenhouse gases in the upper atmosphere.
The phenomenon which happens in a horticultural greenhouse which causes the temperature inside to remain higher than the outside. The infra red radiation coming into the greenhouse from the sun is from a high temperature source and contains a larger proportion of short wavelength infra-red. Glass allows this to pass through easily. The interior of the greenhouse is a low temperature source and emits infra-red of a longer wavelength which passes less easily through the glass, hence the heat energy coming in is greater than that which leaves resulting in an increase of temperature inside. The same effect occurs with the earth as a whole where the layer of upper atmosphere containing carbon dioxide acts in the same way as the glass of a greenhouse.
A greenhouse gas is any gas which, when it gets into the upper atmosphere, causes the greenhouse effect. The most common greenhouse gases are carbon dioxide and methane.
Methane is ordinary natural gas used domestically. It occurs in nature by decay of vegetable material, but also is produced by cattle and sheep in their digestive processes. If it gets into the upper atmosphere it acts as a powerful greenhous gas, many times more powerful than carbon dioxide.
A layer of ozone which is present in the upper atmosphere of the earth and protects the earth from ultraviolet radioation from the sun. Such radiation is harmful to humans and other life forms.
The introduction into the environment of harmful substances.
A way of re-using materials by reducing objects to their basic constituents and then remaking them. Typically applicable to paper, plastic, metals and glass. The term does not normally apply to re-use of the objects themselves (which would be preferable). Recycling saves energy, saves the use of new materials, and saves on the disposal of old objects.
Renewable resources of energy are those which can be used endlessly without depleting the source. Examples are hydraulic power from rivers and dams, and energy from wind, waves, and tides.
Describes something which can be sustained over long time scales without depletion of resources or accumulation of unwanted pollution.
Some people do not realize the difference between the various polluting gases from power stations and motor vehicles. The most obvious ones are those which smell and make us cough, typically nitrogen dioxide and sulphur dioxide. These are irritant, unpleasant and obvious. Carbon dioxide (CO2) however is imperceptible even in quite large quantitities. Most measures taken to clean up emissions from motor vehicles, such as catalytic converters do not affect CO2 and in addition CO2 is produced in very large quantities from combustion of oil and coal. It is mainly CO2 which is responsible for the greenhouse effect.
The big problem with fossil fuels, as compared to wood, is that they are taken from the earth and not replaced. When burnt, the carbon dioxide is released into the atmosphere as a permanent one-off transfer and will not be returned. Wood is different because if a tree is allowed to grow again it will absorb carbon dioxide from the atmosphere to form the carbon in the wood, and there is the potential for an endless cycle resulting in no long term overall increase of CO2 in the atmosphere. The same applies to oil taken from plants.
This is my own attempt to check the claims above based on information from other sources.
My encyclopedia says the area of Antarctica is 15 million sq km. The average depth of ice is 1.5 km (surprisingly large). That gives a volume of ice of 22.5 million cu km.
Next calculate the area over which this would be distributed in order to calculate the additional depth of water.
The radius of the earth is 6378 km. The surface area of a sphere is 4 x pi x r squared. That gives 511 million sq km. The resulting sea level rise would be 22.5 / 511 km = 22500 / 511 metres = 44 metres. That assumes it is spread over the whole surface of the earth and doesn't allow for the areas of land. As a rough calculation it's not far off.
Actually all you need is the average depth of ice on Antarctica and the ratio of its area to the area of the rest of the earth's surface. The above figures give the proportion of the earth's surface occupied by Antarctica as approx 15/500 = 0.03 (3%). Hence the average depth of ice on Antarctica will represent, if spread over the whole earth, 0.03 x 1500 metres, = 45metres.
1 cubic kilometre is a huge cube one kilometre in each direction. It is 1000 x 1000 x 1000 cubic metres.
1 cubic metre of water weighs 1 tonne.
1 cubic metre is 1000 litres.
Population and over-population: population.html
Farming and food: farming.html
Nature and wildlife: nature.html
The contents page for my environmental pages is at:
Site promoted by Al Gore:
Friends of the Earth
www.foe.org - The USA and international site.
www.foe.co.uk or www.foe.org.uk - The UK site.
The Hadley Centre for climate prediction and research.
Ecological site. Estimate your footprint.